Table 3.

Univariate analyses for health behaviours and social variables. Values are numbers (percentages) unless otherwise indicated

Exposures	Cases (n=144)	Controls (n=144)	Matched odds ratio (95% CI)	P value
Regular smoker	47 (33)	45 (31)	1.1 (0.6 to 1.8)	0.8
Multiple close contacts who smoke*	104 (72)	92 (64)	1.6 (0.9 to 2.7)	0.11
Regular consumption of illegal drugs (once a week or more)	23 (16)	13 (9)	2.3 (1.0 to 5.2)	0.06
Any alcohol consumed*	123 (85)	113 (78)	1.6 (0.9 to 3.0)	0.13
Regular partner	60 (42)	54 (38)	1.2 (0.7 to 1.9)	0.45
Multiple intimate kissing contacts*	42 (29)	22 (15)	2.1 (1.2 to 3.7)	0.009
Shared bedroom*	96 (67)	74 (51)	2.1 (1.2 to 3.6)	0.006
Lives in dormitory accommodation	10 (7)	8 (6)	1.4 (0.4 to 4.4)	0.6
Attended bar or party*	128 (89)	115 (80)	2 (1.0 to 3.9)	0.04
Daily visit to friends home*	31 (22)	15 (10)	2.3 (1.2 to 4.6)	0.01
Attended one or more religious ceremonies*	6 (4)	15 (10)	0.3 (0.1 to 0.9)	0.04
Socioeconomic status
Categorical variable based on home and car ownership (odds ratio relative to owning neither home nor car)†
No home and no car ownership	12 (8)	12 (8)	1.0	—
One or more cars but do not own home	22 (15)	16 (11)	1.4 (0.5 to 4.4)	0.5
Own home but no car	7 (5)	5 (4)	1.4 (0.3 to 6.6)	0.6
One or more cars plus own home	102 (71)	110 (76)	0.9 (0.4 to 2.3)	0.8
Subject's occupational status (odds ratio relative to being employed):
Employed	36 (25)	38 (27)	1.0	—
University student	50 (35)	46 (32)	1.2 (0.6 to 2.4)	0.7
School student	52 (36)	51 (36)	1.1 (0.4 to 2.8)	0.8
Others	5 (4)	8 (6)	0.6 (0.2 to 2.5)	0.5

^*In the fortnight period before illness (cases) or interview (controls).

^†In most cases, this refers to the parents—see methods for clarification.